Objective To investigate the developmental feasibility of early human fetal testes (<3 months) using xenografting technique and to acquire an accessible donor derivation that is essential for studying human germ cell development. Methods Nine testes from 10-13 weeks aborted fetus were grafted under the back skin of 6 castrated nude mice. Grafts were collected at different time point according to the growth of the donor tissues and the health condition of the recipients. Morphological and histological analyses were performed for the observation of the development of grafted immature testicular tissues. Results The mass of grafts was increased from about 5-7mg to 84.1mg (the biggest). Six of 9 testes were to be in developing. Histological observations showed a significant expansion of seminiferous tubules from (44.26±3.14)μm to (77.69±7.47)μm. Cells dispersedly distributed in seminiferous cords at the time of grafting migrated towards the basal part of seminiferous epithelium. Some germ cells with spermatogonium-like characteristics located on the basement membrane. Sertoli cells were in stages from immature into matured with abundant cytoplasm which were orderly arranged around spermatogonia forming a niche-like structure. Conclusion Testes from early aborted human fetus grafted under the back skin of castrated nude mice showed further development and therefore could be used as an easier accessible donor tissues for the investigation of human spermatogenetic mechanism.

Objective To establish a fluorescent polymerase chain reaction (PCR) method for rapid, sensitive and specific determination of -88/-123 polymorphisms in Myxovirus resistance protein A (MxA) gene promoter so as to provide molecular biology tool for optimized interferon-a treatment in chronic hepatitis B patients. Methods Hepatitis B virus (HBV) genotyping,serum HBV DNA level,and- 88/- 123 polymorphisms in MxA gene promoter of patients who had been treated with interferon-α were detected. The statistical analysis was done by using SPSS software to understand the relationship between MxA gene polymorphisms and interferon-α treatment. Afterwards, an optimal fluorescent PCR system was established to determine -88/-123 polymorphisms in MxA gene promoter. The sensitivity and the specificity of this system were confirmed by DNA sequencing. P-value of chi square test, odds ratios of regression analysis and 95% confidence intervals were employed. Results Patients with- 88 G/T and - 123 C/A in the interferon-stimulated response element in MxA gene promoter were interferon-α sensitive, while patients with - 88 GIG and - 123 C/C were not interferon-α sensitive. The coincidence rate of this system was 99.65% in comparison with DNA sequencing.Conclusion MxA gene polymorphisms could be rapidly and sensitively determined by this fluorescent PCR system.

Objective:To explore the effect of the microenvironment induced by damaged mouse hepatic cells on the conversion of human umbilical cord blood-derived cells into hepatocyte-like cells. Methods: A hepatic injury-like microenvironment was mimicked using carbon tetrachloride damaged mouse hepatic cells, where mononuclear cells (MNC) from human umbilical cord blood were cultured in a compartment separated by trans-well membrane. Histochemical staining, reversed transcription-polymerase chain reaction (RT-PCR) and gene sequencing were performed for the information on the conversion of human umbilical cord blood MNC. Results: A number of PAS positive stained cells in MNC co-cultured with damaged mouse hepatic cells were observed after 72 h. Cells expressing mature hepatocyte markers, human albumin (hALB) and human GATA-4 (hGATA-4) mRNA were detected by RT-PCR, which was further confirmed with sequencing. Relevant control groups, MNC co-cultured with normal mouse hepatic cells and MNC cultured alone remained negative. Conclusion: The culture system using damaged mouse hepatic cells as stimulator could be a potential in vitro system for the conversion of human umbilical cord blood-derived cells into hepatocyte-like cells.

OBJECTIVETo investigate the development of xenografted primitive human germ cells by using fetal testicular tissues as donor tissues and an immunodeficient mouse as the recipient.

METHODSTesticular tissue fragments of a 26-week fetus were grafted under the back skin of a castrated immunodeficient mouse. Grafts were taken out after 135 days and processed for morphological and histological analyses.

RESULTSThe mass of grafts grew from about 1 mm in diameter and 5 mg in wet weight to about 3 mm and more than 20 mg 135 days after grafting. Histological observations showed a significant expansion of seminiferous tubules after grafting (80 +/- 25 microm in diameter) in comparison with seminiferous cords at the time of grafting (60 +/- 15 microm in diameter). The seminiferous cords developed into seminiferous tubules with the epithelial border and lumen. After 135 days of grafting, most of the dispersedly distributed primitive Sertoli cells and germ cells migrated to the basal part of seminiferous epithelium, located on the basement membrane and few of germ cells differentiated into spermatogonia.

CONCLUSIONHuman fetal testicular tissues could survive and continuously develop after being xenograft into castrated immunodeficient mice.

Animals ; Fetal Tissue Transplantation ; Humans ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Spermatids ; growth & development ; Testis ; cytology ; transplantation ; Transplantation, Heterologous

Objective To study the effect of psoralen isoflavone on the treatment of PC12 cells injured by Aβ and the mechanism on the effect of the psoralen isoflavones on the expression of related proteins. Methods The PC12 cells were divided into blank group, model group, E2 group, and psoralen isoflavones group by random number table method, In addition to the blank group the rest of each group culture medium were added 20μmol/L of Aβ25-35 modeling, The E2 group was added to the 10-3μmol/L oestrogen and psoralen isoflavones group for the intervention of 102-10-6 μmol/L.The proliferation rate of PC12 cells was detected by MTT assay, and the expression of APP, BACE1, ERβ, p-ERK and Aβ protein was detected by Western Blot. Results Compared with the model group, the proliferation of PC12 cells induced by 10-1μmol/L of psoralen isoflavone increased (101％ vs. 52％, P<0.01); The expression of p-ERK (0.751± 0.066 vs. 0.364 ± 0.015), ERβ(0.756 ± 0.105 vs. 0.337 ± 0.045) increased significantly (P<0.01); APP (0.382 ± 0.039 vs. 0.479 ± 0.015), BACE1 (0.517 ± 0.024 vs. 0.622 ± 0.029), Aβ (0.430 ± 0.032 vs. 0.581 ± 0.030) expression amount were significantly lower (P<0.05). Conclusions Psoralen isoflavones have a certain therapeutic effect on PC12 cells injured by Aβ.

Since 2010, the incidence of severe fever with thrombocytopenia syndrome (SFTS) has been increased. Owing the progress in diagnosis and treatment, the overall mortality of SFTS in China has decreased, while the mortality in critical SFTS patients is still high. In order to provide guidance and working procedures for clinicians to diagnose and treat critical SFTS, the National Medical Center for Major Public Health Events invited experts to discuss and formulate this consensus based on their experience and up-to-date knowledge on SFTS.

Novel coronavirus Omicron variant infection can cause severe illness and even death in certain populations. Omicron variant infection may lead to systemic inflammatory response, coagulation disorder, multi-organ dysfunction and other pathophysiological changes, which are different from other Novel coronavirus variants to a certain extent, so therapeutic strategies should not be the same. The National Medical Center for Major Public Health Events invited experts in fields of infectious diseases, respiratory medicine, intensive care, pediatrics and fever clinic to develop this quick guideline based on the current best evidence and extensive clinical practices. This quick guideline aims to standardize the diagnosis and treatment of novel coronavirus Omicron infection, and to improve the disease management abilities of clinicians.